There was never much doubt that Sidney Crosby would eventually come to terms on a contract to play out the remainder of his career in Pittsburgh, and on Thursday, that was exactly what happened; the Penguins’ captain agreed to a 12-year, $104.4 million extension that will be signed on Sunday and take effect at the start of the 2013-14 season.

At $8.7 million a year, Crosby will carry the same salary cap hit he did in his previous contract. When you’re dealing with a sum of money so large, it is okay to leave a few dollars on the table to fit numerical superstitions: Crosby was born on August 7, 1987—8/7/87—and has worn No. 87 on his jersey for his entire NHL career.

Because his birthday is so easy to remember, everyone knows that Crosby will turn 25 this summer and will be 26 at the start of his new contract. That’s everyone including Penguins general manager Ray Shero, who said on a Thursday conference call that he believes Crosby’s “best hockey is ahead of him.”

Historically, that is not the case.

Crosby ranks fourth on the NHL’s all-time list of per-game scoring, with 1.403 points per game, a total that trails Wayne Gretzky (1.921), Mario Lemieux (1.883) and Mike Bossy (1.497), with Bobby Orr (1.393) rounding out the top five. Plotting out those Hall of Famers’ annual scoring totals shows just what a challenge Crosby faces.

The vertical axis on this chart shows the dividing line between pre-age 26 performance and what happens at the age when Crosby’s new deal comes into effect. While the tracks vary by player, the one clear thing is that each player peaked on the wrong side of the line, as far as Crosby and the Penguins are concerned.

Gretzky owns the only four 200-point seasons in NHL history, and the last one came in 1985-86, when a 25-year-old Great One set the league record at 215 and won the seventh of his eight consecutive Hart Trophies. While he led the league in scoring four more times, and wound up a nine-time MVP, Gretzky never again approached the heights of his early 20s.

Of the other players in the top five, Bossy had the steadiest performance after age 26, with 117-123 points for four straight seasons until the last campaign of his career, when he had 75 points in 63 games for the 1986-87 Islanders. Back injuries then led to the end of Bossy’s time in the NHL at 30, just as Orr’s knees sent him into early retirement.

Lemieux’s career had far more twists and turns, health-wise, from back problems to cancer. His 161 points in 1995-96 trail only Gretzky’s 163 points in 1990-91 for the highest-scoring season by a 30-year-old in NHL history, but like Gretzky, Lemieux’s top seasons were in his younger days—168 points at age 22 in 1987-88, followed by 199 points the next year. The Stanley Cups that Lemieux won in Pittsburgh came at age 25 and 26.

Gretzky and Lemieux in particular were affected by changes in the NHL, as scoring dropped precipitously through the 1990s. Still, even looking at players who are closer to being Crosby’s contemporaries, the trend is clear—Crosby faces a challenge to play the best hockey of his career after his new deal begins.

Of the active top five in points per game, Crosby obviously leads, while Evgeni Malkin is 25 years old and Alex Ovechkin, in a precipitous scoring decline the past two seasons, is 26. Jaromir Jagr led the NHL in scoring every season from 1997-98 through 2000-01—ages 25 through 28—but his top scoring season was 1995-96, when he had 149 points. Teemu Selanne, who had his career high in points as a rookie, rounds out the top five in active per-game scoring, even with only one 100-point season after his age 26 campaign.

Added into the chart of Crosby’s contemporaries are Eric Lindros, whose career was derailed by concussions, and Joe Sakic, a first-ballot Hall of Famer this year.

Lindros is the basis for comparison for Crosby that has to worry everyone in Pittsburgh when it comes to Crosby, who has played only 30 games, including playoffs, since the beginning of 2011. Sakic is the player whose career path Penguins fans might most want Crosby to mirror, as he won his first Cup at 26 and another at 31, the latter following a 118-point season that represented the second-highest scoring total of Sakic’s career.

Still, even Sakic could be said to have peaked early. He had six 100-point seasons, but only two after his 120-point career high for the 1995-96 Colorado Avalanche at age 26. That’s the same career high that Crosby set—at the age of 19, his second year in the league. There is no certainty that he won’t be able to approach that again, but history is not on the side of the expectations Shero put on him.